The risk of perioperative stroke in patients with asymptomatic carotid bruits undergoing peripheral vascular surgery.

Three hundred patients without neurologic symptoms had 374 elective peripheral vascular procedures and they were screened preoperatively for incidental asymptomatic carotid bruits prior to surgery. The bruits were hemodynamically evaluated with the GEE-OPG. A bruit was considered hemodynamically significant if the OPG test was positive. Seventy-four patients (24.7%, 74/300) were found to have 118 carotid bruits. Twenty-five (22.3%, 25/112) of the 112 bruits with OPG studies were hemodynamically significant. There were three perioperative strokes that occurred for an incidence of 0.8 per cent (3/374). There was no stroke in patients without bruits and with nonhemodynamically significant bruits. The incidence of perioperative stroke in patients with hemodynamically significant bruits was 16 per cent (3/19). There is a subgroup of patients with hemodynamically significant carotid bruits who are at high risk for perioperative stroke.

The asymptomatic carotid bruit.

Management of the asymptomatic carotid bruit remains a controversial subject. The purpose of this study is to determine whether or not such bruits are important risk factors in the evolution of stroke. Since April 1977, 87 patients with 131 asymptomatic carotid bruits were evaluated with the Gee oculoplethysmography (OPG). Eleven bruits (8.4%) were hemodynamically significant (ophthalmic artery/brachial artery systolic pressure index below 0.69 or a difference of 5 mm Hg or more between the eyes). The patients were reevaluated at 6-month intervals. The mean follow-up was 34 months (range, 1-60 months). During this period, 14 bruits (11.6%) that initially were nonhemodynamically significant (NHS) later became hemodynamically significant (HS). Patients with asymptomatic carotid bruits had a stroke incidence of 10.3 per cent. Patients with HS bruits had a stroke incidence of 24 per cent and a transient ischemic attack (TIA) incidence of 16 per cent, which were significantly higher (P greater than 0.01) compared to the patients with NHS bruits (4.8% incidence of stroke and 3.2% incidence of TIA). Nine patients (10.3%) developed strokes without antecedent TIA and six patients (6.9%) developed TIA. The strokes occurred in the cerebral hemisphere supplied by the carotid artery with HS bruit in three of six patients. The strokes in three patients with NHS bruits were on the same side of the bruits. The TIAs developed in four patients with HS bruits and in two patients with NHS bruits. The authors conclude that the patient with an asymptomatic HS carotid bruit has a high risk of developing a stroke and that surgical treatment is warranted.

Iatrogenic entrapment of the femoropopliteal bypass.

Three cases of infragenicular femoropopliteal bypass grafts are presented in which iatrogenic entrapment of the distal portion of the graft occurred between the medial head of the gastrocnemius muscle and the posterior surface of the tibia. The condition should be suspected if ischemia of the leg develops postoperatively when the knee is hyperextended and is improved when the knee joint is flexed. Measurements of the ankle pressure index or Pulse Volume Recorder tracings at the ankle in both flexed and extended positions will confirm the diagnosis. The entrapment of the bypasses in these three patients was easily corrected by transection of the medial head of the gastrocnemius muscle. Relief of the occlusion of the bypass can be easily demonstrated by noninvasive studies.

Oculoplethysmography. Evaluation of patients with transient ischemic attacks from internal carotid artery disease.

Oculoplethysmography was used to evaluate 66 patients with transient ischemic attacks prior to cerebral angiography. Fifty-eight (87.9%) symptomatic internal carotid arteries had anatomically significant stenosis. Only 69 per cent of these 58 arteries had positive OPG test. Thirty-one per cent of the arteries were well compensated hemodynamically with collaterals and had a false negative test. A negative OPG test does not rule out an anatomically significant internal carotid artery stenosis.

Toe pulse study in ischemic arterial disease of the legs.

The toe pulse reappearance time study for ischemic arterial disease of the lower limb is an easy and accurate test which has great usefulness as a rapid screening method. It is well tolerated by the patients with ischemic arterial disease. Results of the test reflect the total blood flow, including that through the collateral vessels. They determine the severity of the occlusive arterial disease of the lower limb but do not determine the specific levels of arterial occlusion. A principle area of usefulness of the test is for patients who cannot exercise, such as those with a painful ulcer, incapacitating claudication and cardiopulmonary disease.